Kurotsuki Renya spent an entire day mastering the basic grip and ready stance of Zanjutsu, under the patient guidance of Abarai Renji. On the second day, Renji began to instruct him in footwork fundamentals—an essential foundation for all Shinigami combat.
There are many methods in Zanjutsu training, and Renji taught him the six fundamental movements: Ayumi-ashi (walking step), Okuri-ashi (sliding step), Tsugi-ashi (pushing step), Hiraki-ashi (opening step), Tobi-ashi (leaping step), and Yoko-ashi (side step).
Of these, the Okuri-ashi—the sliding step—was the most frequently used. The foot doesn't lift off the ground but slides across it, reducing body sway and maintaining a stable stance, making it easier to counter or defend.
It took Renya two days to stabilize his posture while maintaining the sliding step with a training bokken in hand. During this, he was required to maintain the proper kendo stance.
Renji then introduced Ayumi-ashi, or the stepping walk. It was similar to Okuri-ashi, but used in longer movements and transitions.
Next came Tsugi-ashi, where one foot—usually the left—follows after the lead foot with a quick, precise motion. If advancing, the right foot slid first, followed by the left. If retreating, it reversed.
Diagonal movement was also taught, involving small slide-steps while keeping the upper body posture intact. A key rule was not to move both feet simultaneously—one foot always remained as a base for balance.
Renya spent five more days mastering Tsugi-ashi.
After that came Hiraki-ashi, or opening step, used to pivot the body for offensive or defensive reorientation. This allowed the practitioner to shift directions while keeping balance. Renya needed only two days to pick it up.
Then came Tobi-ashi (jump step), a more explosive movement meant for sudden bursts forward or back. The hind foot draws up to the lead before launching forward. This movement could surprise an opponent and was known as a "stolen step" in Shinigami duels.
After Renya grasped that, Renji taught Yoko-ashi, the side step—quick lateral movement that helped maintain distance or circle around an enemy.
All six footwork types took ten days for Renya to learn. And as he trained, his spiritual pressure began to increase gradually—compressed and condensed through repeated exertion.
In Zanjutsu, footwork is critical. Without it, the rest of the swordplay is unsteady. With a firm foundation, Renya was ready for suburi, or repetitive striking.
The movements for suburi relied heavily on the previously practiced footwork. As Renya stepped forward using Okuri-ashi, he had to control his breath, shift his center of gravity forward, exhale sharply, and coordinate his arms to drive the bokken forward.
Control of the hands was just as essential. When the sword first moved, the left hand's pinky had to grip tightly while rotating slightly inward. As the swing completed, the right hand rotated inward to channel the energy forward through the blade tip.
The force had to travel from the ground through the legs, hips, torso, and arms—culminating in a precise strike. This full-body effort not only improved technique, but also greatly stimulated reiatsu compression.
There were two types of suburi Renya was required to perform:
Endurance-based, where he focused on how many swings he could perform in a session
Explosive-based, where he tried to maximize swings in a short time frame
Lucia—more accurately, Rukia Kuchiki—emphasized both. But especially the first: learning to swing consistently while not leaking spiritual energy. That, she said, was the hallmark of true control.
It was a difficult challenge for a boy of just eleven.
Renya trained alone, holding his bokken in an open clearing. One swing. Then two. Five. Ten. The first ten came easily. But afterward, the weight of the sword and fatigue set in.
Eleven… twelve… twenty.
At twenty-one, his arms began to ache, and his swing slowed. He paused and focused on replenishing his spirit particles, drawing in reishi from the air to restore his stamina.
Then he started again. Over and over, reiatsu consumed and replenished, muscles strained and rebuilt.
Thirty-five… forty… forty-seven… fifty.
After two full weeks, Renya was able to complete a full set of fifty suburi swings—meeting Rukia's requirement.
But suburi was only the beginning. Now came kumitachi, or paired sword drills.
Rukia offered to be his sparring partner. Standing in front of him, she held a training sword and gave a calm but serious look.
Renya stood three steps away. He held his bokken in both hands, inhaled deeply, and stepped forward. His right foot planted firmly, left foot sliding into position, shoulders turning, and arms swinging the sword down toward her.
Rukia reacted swiftly. She slightly adjusted her stance and deflected the strike by angling her blade's side—using only minimal force.
The deflection caused Renya's swing to stagger. In that moment, Rukia pivoted her right foot, and launched her counter. Her bamboo blade surged forward in a blur.
Wind rushed past Renya's cheek. He instinctively flinched.
But the strike never landed. Rukia's weapon stopped precisely one centimeter from his chest.
She withdrew and shook her head. "You lost control in the middle of your swing. Your hands weren't in sync, and your strength scattered. Second, you didn't prepare for the retreat. Zanjutsu isn't just about attacking—it's also about retreating at the right moment. If your sword is blocked, you must immediately pull back to avoid the counterattack."
"I understand."
Renya committed the lesson to memory. Rukia nodded. "Again."
With her guidance, Renya sharpened his control and precision. Soon, he could execute suburi movements with near-instinctive fluidity.
Next, Renya practiced targeted strikes:
Men – head strike
Kote – wrist strike
Do – torso strike
Tsuki – throat thrust
These were the fundamental targets of Zanjutsu. Simple in theory, but difficult to master.
Rukia and Renji didn't teach him any advanced styles like Itto-ryu, Shinto-ryu, or Yagyu Shinkage-ryu—only the basics. The Shinigami who had passed through the Rukongai previously had left them with this knowledge before returning to the Gotei 13.
Still, these techniques gave Renya a functional ability to defend himself, which was crucial in Rukongai's chaotic environment.
Alongside this, he learned how to channel his spiritual energy. By coating his bokken with spiritual pressure, he could make it hit faster and harder—mimicking the flow of reiatsu into a real Zanpakutō.
Although only eleven, Renya's training and control allowed him to hold his own against both Renji and Rukia—especially by cleverly managing his reiryoku to enhance his speed and strength.
With time, Renya's spiritual density had increased significantly. If he continued, he believed he could eventually reach Grade 5 spiritual pressure—the entry-level of Shinigami trainees.
At this point, three months had passed since Renya had arrived in Soul Society.
And with winter descending upon the Rukongai, a quiet resolve had begun to take root in his heart.